This invention pertains generally to an orthopedic brace and more particularly to a knee brace.
The human knee is the largest joint of the body, but due to its natural structure is the most vulnerable. The leg consists principally of a lower bone called the tibia and an upper bone known as the femur. The femur and tibia are hinged together at the knee joint. The knee joint includes femoral condyles supported in engagement with bearing like pads, called the medial and lateral menisci, positioned on the upper end of the tibia. The joint is held together by numerous ligaments, muscles and tendons, including the lateral ligaments and internal ligaments. The patella is a similarly supported bone positioned in front of the knee joint and acts as a shield for it. The joint is suspectable to damage if over extended or subjected to lateral or rotational trauma. Such trauma may result in anterior or posterior cruciate ligament injury or severance, medial/collateral ligament injury and/or medial/lateral menisci injuries. Damage to ligaments or other elements of the knee structure may cause the leg to become unstable and allow lateral wobble of the knee joint.
To promote healing, knee braces that prevent medial and laterial instability are used. Normally these braces: 1) provide derotation bracing to restrict rotation of the tibia relative to the femur about the knee joint; 2) prevent displacement of the tibia when the leg is flexed; and 3) protect collateral ligaments by using rigid vertical bracing elements on the medial and lateral sides of the knee joint.
U.S. Pat. No. 4,793,333 to Marquette discloses one such knee brace. The knee brace includes a tibial shell and a femoral shell joined together by a pair of joints. The femoral shell is configured to engage a posterior portion of the thigh and is secured to the leg of a wearer by a strap including hook and loop type fasteners. The tibial shell engages an anterior portion of the lower leg and is also secured by a strap including hook and loop fasteners. The joints are located to the medial and lateral sides of the knee joint. However, the objectives stated above are not well achieved since the bracing elements of the knee brace do not use the bones in the leg as a reference. The brace is attached to the flesh surrounding the knee joint and is therefore unstable relative to the leg bones.
It is evident that there is a continuing need for improved knee braces. Specifically, there is a need for a lightweight brace referenced mechanically to the tibia and femur that provides the stability necessary to mimic the support no longer provided by muscles in the injured knee.